ANNAPOLIS, Md. (WJZ) — Governor Larry Hogan spent much of the past week touring the Eastern Shore. That included greeting people unmasked while on the Ocean City boardwalk and speaking at the Maryland Association of Counties, which was attended by leaders from across the state.

Then came news that four of his staff members tested positive for COVID-19. One who initially received a positive rapid antigen test later had a PCR test and was found to be negative.

The governor and lieutenant governor have both tested negative for the virus.

Governor Hogan also attended an event with the Washington, DC mayor and Virginia governor.

During an event at BWI Thurgood Marshall Airport Tuesday, Hogan said he was headed to Colorado for a National Governors Association conference. He said he would meet with Jeff Zients, The White House COVID-19 Response Coordinator, while there.

Hogan, a cancer survivor, already received his third vaccine dose, which he revealed to CBS’ Face the Nation on Sunday.

“I had a cancer of the immune system so I got it on Monday [Aug. 16]. I feel great,” Hogan said on the program.

The governor’s office said all members of Mr. Hogan’s staff are fully vaccinated and are following all CDC guidance on quarantining and contact tracing.

“All those affected are feeling fine,” tweeted Hogan spokesperson Kata Hall.

Dr. Bill Moss with Johns Hopkins told WJZ Investigator Mike Hellgren such ‘breakthrough’ infections among the fully vaccinated are rare but do happen.

“There may be a component of some waning immunity for those who are vaccinated early on, and that was the argument that The White House has made about the need for booster doses,” Moss said.

He noted the Delta variant is causing an increase in cases among the fully vaccinated but “the vast, vast majority of these breakthrough infections among fully vaccinated individuals are mild.”

Maryland reports 9,079 infections among the fully vaccinated. Among those, 733 people were hospitalized, representing 5.6% of all COVID-19 cases hospitalized.

There were 76 deaths among the vaccinated, representing 5% of all lab-confirmed COVID-19 deaths in Maryland.

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The Maryland Department of Health said approximately 6.5% of all confirmed COVID-19 cases in Maryland since January 2021 have been among fully vaccinated individuals.